Defecating more than normal? And in the house?

Hey guys, wanted to pick your brains on a recent issue my roommate's dog is having. Within the last week or so, Guinness is having on and off episodes of defecating in the house. He's doing it in the basement, which is where he will sometimes vomit (he thinks he's going to get in trouble for doing so). The thing is, it isn't just that he's defecating in the house, but he seems to be defecating more often. The other day we found two piles downstairs, and he still went outside his normal amounts. Poop is solid, no apparent blood/mucous, he hasn't had any changes in food, the weather has never influenced him (he is usually housebroken without any issues, even in our MN winter). He's been vomiting a bit more lately, but he's always been one who will vomit bile if he doesn't eat for a while or is forced to wait for breakfast after waking up early and psyching himself out. The neighbors put out bread for the squirrels that he gets pieces of often, so he could easily have picked up a parasite from eating food off the outside ground. Other than that, I can't think of what would cause an increase in defecation/stool amount. Maybe it's behavioral. We're taking him to the vet tomorrow, but figured it wouldn't hurt to ask you guys as well. Oh, and nothing else is off. Energy is good, and he's eating/drinking well.

Is he drinking more than usual?

It's hard to tell, but I don't think so. He's always been a pretty big drinker, though...and maybe that's been an increase over the last few months or so, but not sure.

An increase in excretion that can't be accounted for by an increase in intake or change of diet would proabably indicate some change in metabolism. So the vet exam is a good thing to check those possibilities out.

However, first you need to be 100% sure that he is excreting more, quantity-wise. When he goes out, is there stuff so exiting that he hurries to do his busisness so that he can go and play, or rush back inside, or claim a treat for pooping?
It's possible he is not really finishing properly and then has to sneak off and complete the emptying out later. If that is the case you will have to retrain and get him out of that habit.

Thanks for the follow up response, Angela. It is highly possible it is behavioral. His normal routine is out to pee around 5:45 am, rush in to have breakfast, out again to pee/poop at about 9:30. Then he's out around 2, sometimes later, and random times during the night. It is possible he's getting to distracted outside, especially now that it's getting nice out.

He looked perfect on physical exam at the vet's tonight. I work there, so he's coming with tomorrow so they can do a work up, just in case (fecal float, giardia test, gram stain, and CPL). They're testing for pancreatitis because he does vomit sometimes, and did yesterday at an odd time. He also has a history of having an upset stomach, and the vet says she sees a lot of dogs with various degrees of pancreatitis who have a history of having sensitive stomachs.

So even though he's barely been vomiting and no diarrhea, he tested a faint, but definite, positive for pancreatitis. He also had no abdominal pain. Good that it isn't more severe, and we can trace it back to a bone he had a week or so ago. Some GI antibiotics and a low fat diet for 10 days, and he should be feeling better.